Marine Hermit Crabs....lots of questions

[flutinkat]

Great, thank you! Some more questions (sorry, I'm not running out yet!)

 

1) How much of a water change should I do weekly?

2) What kind of salt should I be using? Will Instant Ocean be sufficient?

3) Is macro algae necessary? Are there easier alternatives? I'm looking for low-maintenance since I routinely work 60-hour+ weeks.

4) What can I do to test alkalinity and salinity?

5) A friend who has a nano reef told me sponge media works well. Is this true?

 

My current favorite from the crabs I've seen and liked is the dwarf zebra hermit crab...I'm thinking three scarlets or four dwarf zebras. I checked out the other kinds but I'm just not a fan.

 

Thanks again for everything!

[seabass]

1) How much of a water change should I do weekly?

 

10 to 15% every week is pretty typical for fish tanks. It kind of depends on your nitrate level. Change out enough to keep nitrate at 10ppm; however with macro algae, you might not have to do them as frequently.

 

2) What kind of salt should I be using? Will Instant Ocean be sufficient?

 

Instant Ocean is a good choice for this type of tank.

 

3) Is macro algae necessary? Are there easier alternatives? I'm looking for low-maintenance since I routinely work 60-hour+ weeks.

 

You can totally do it without algae. It will be much easier. If you don't mind the look of just rock, then that's all you'll need. You will need some flow in the tank, so you should get a powe head (10 to 30 times turnover should be good).

 

What type of light will this have? A PAR30 LED reef bulb would be enough to support some live coral.

 

4) What can I do to test alkalinity and salinity?

 

They sell alkalinity test kits, but without coral, there won't be much consumption. The alkalinity of Instant Ocean salt mix will be sufficient for the crabs.

 

You need a hydrometer at a minimum to test specific gravity. A calibrated refroctometer will be more accurate, but a hydrometer would be good enough.

 

5) A friend who has a nano reef told me sponge media works well. Is this true?

 

If you leave a filter sponge in too long, it will become a biological filter. We are suggesting that the live rock will be your biofilter, so you don't want additional biofilters. If you use a sponge as a mechanical filter, clean it out a few times each week.

[fretfreak13]

I saw your fiddler crab question was unanswered. Here's a nifty little care sheet.

 

http://www.freewebs.com/fiddlercrabcare/

[flutinkat]

Thanks for the info! I don't think I'm going to get fiddlers - I know plenty of crab people who keep them but I'm just not sure I want one. I really appreciate the information, though, and new knowledge is always interesting.

Just to make sure I fully understand:

Will I need anything beyond my current setup for just live rock and crabs? Does live rock need a light? I have a light on the pools that's designed for the plants and animals to flourish, and there is low light UVA and UVB in the tank from a window.

Could I replace the filter with a non-sponge media or do I have to remove it completely? It's frustrating to spend 20 bucks on a filter and then not use it, but I'll do that if that's what I need to do.

Can I use a bubbler or a filter without media for water flow instead, or is a power head necessary?

I'm a litle concerned about the hermit's need for algae consumption if I don't add macro algae. Will the nitrates produce that?

 

I'd love to get some of that kelp on the website, but they are out of stock for now. I'll ask at the local fish store as well.

 

Thanks!

[fretfreak13]

Thanks for the info! I don't think I'm going to get fiddlers - I know plenty of crab people who keep them but I'm just not sure I want one. I really appreciate the information, though, and new knowledge is always interesting.

 

Just to make sure I fully understand:

Will I need anything beyond my current setup for just live rock and crabs? Does live rock need a light? I have a light on the pools that's designed for the plants and animals to flourish, and there is low light UVA and UVB in the tank from a window.

Could I replace the filter with a non-sponge media or do I have to remove it completely? It's frustrating to spend 20 bucks on a filter and then not use it, but I'll do that if that's what I need to do.

Can I use a bubbler or a filter without media for water flow instead, or is a power head necessary?

I'm a litle concerned about the hermit's need for algae consumption if I don't add macro algae. Will the nitrates produce that?

 

I'd love to get some of that kelp on the website, but they are out of stock for now. I'll ask at the local fish store as well.

 

Thanks!

 

Live rock, the salt, and the substrate if you plan on having one. No need for any special lights for LR, but having lights on them isn't bad either. There's no difference in that department.

 

If you want, crush up some base rock and throw it in your filter. Wont hurt and will still have surface area for bacteria.

 

Yes, you can. I'd stay away from the bubbler because of salt creep when they pop at the water surface though.

 

Not quite sure what you mean by that. Macro algaes are the easiest things in the world to grow, really. Throw a light on them and you're good, plus there are many STUNNING ones out there. Look up blue ochtodes, caulerpa prolifera and flame algae.

 

Just a random note that I've learned recently. I don't know what your other hermits need but I saw you mentioned you get UVB from a window? I've been researching chameleons and they need UVB light to help their bodies process calcium or they'll get very sick. While researching I've found that UVB light will not pass through glass/plastic (ie. your window if its closed). If for some reason you are actually looking to specifically get UVB light for one of your critters, you'll need a different source (we use reptisun fluorescent bulbs). This is why chameleon cages are screen rather than glass, or at the very least the top is. =) Just wanted to let you know in case you're looking to use UVB for some reason and didn't know that!

[seabass]

Will I need anything beyond my current setup for just live rock and crabs?

You need flow in the tank. I think you said it's a 5.5gal so between 55 and 110gph is plenty.

 

I think you said it has a Tetra Whisper internal filter (which is 20gph). I'd get add a little more flow.

 

Does live rock need a light? I have a light on the pools that's designed for the plants and animals to flourish, and there is low light UVA and UVB in the tank from a window.

No live rock doesn't need supplemental light. The indirect light might be enough for some micro algae to form on the rock.

 

Could I replace the filter with a non-sponge media or do I have to remove it completely? It's frustrating to spend 20 bucks on a filter and then not use it, but I'll do that if that's what I need to do.

The filter is fine to use (either with or without the stock cartridges). You could put some activated carbon in a media bag instead of buying the stock cartridges. If you do use the cartridges, just rinse them out a couple of times a week.

 

Can I use a bubbler or a filter without media for water flow instead, or is a power head necessary?

I'm a litle concerned about the hermit's need for algae consumption if I don't add macro algae. Will the nitrates produce that?

You can run the filter without media (for flow). However, you want about 55gph, so you might still want a small powerhead (or a bigger filter).

 

I wouldn't worry too much about having algae for them to consume. They will do fine without it. Some micro algae will probably form on the rocks for them to consume. Plus there is some algae in a number of the food pellets on the market.

[fretfreak13]

Also...we love picturesss.

[Mr. Microscope]

One note, play sand contains a lot of silicates. You may have algae issues in that tank.

[flutinkat]

These are the lights already on the tank, which I was told were good for the plants. Are these acceptable for macro algae? If not, I'm fine getting the new ones, but again, saving money where it's responsible to do so would be nice.

http://www.amazon.com/gp/product/B0042UN1U0/ref=oh_details_o01_s00_i02?ie=UTF8&psc=1

 

Good to know about the playsand - will the shrimp take care of that?

 

I'm still a little confused about the salt creep issue and why it's bad. I've dealt with it before (we call it salt deposits) and it basically means you just have to wipe down the glass once a week or so. Will this not take care of it?

So to be very clear, once I get live rock, remove the sponge, but keep the filter for flow?

 

Sorry if I sound like a broken record, but I want to be 100% sure I understand.

 

I did go to the fish store today and talk to the specialist/owner, who basically told me that a 5.5g reef with even just a few hermit crabs would not be responsible/ethical to keep due to the delicate nature of all marine animals, even snails. Even with the live rock, correct water flow and some macro algae, he says they would still die. If what he says is true, I'll save all this knowledge and set up a 20g reef a bit later. However, if it's nonsense, would someone please let me know? I don't want to depreciate the value of life for any animal. If this is true, how can I prevent the tank being overgrown by algae, preferably without chemicals?

 

About the UVB - that's really good information to know, so I'll have to find an alternative. There's a lot we don't know about land hermits, and need for UVA and UVB is part of that. :/ It's less simple for them, since their whole tank has to be pretty much enclosed for high humidity control, but I'll see if I can find a workable solution. There's a specific species I have (http://www1.prometheanplanet.com/rediscoveringdarwin/wp-content/gallery/pictures-from-the-expedition/strawberry-hermit.jpg) that is new to captivity and usually is only expected to live 1-3 years in captivity, and I have a strong suspicion that a lack of ammonia-free water and natural sunlight is why. However, the official word is as long as their tank is exposed to any level of sunlight, they are fine - seems like an oversimplification to me.

 

Again, thanks for all the responses! I'm slowly working my way through the libraries still, but I'm sick today and it is hard for me to keep ahold of complex ideas.

[RC1313]

These are the lights already on the tank, which I was told were good for the plants. Are these acceptable for macro algae? If not, I'm fine getting the new ones, but again, saving money where it's responsible to do so would be nice.

http://www.amazon.com/gp/product/B0042UN1U0/ref=oh_details_o01_s00_i02?ie=UTF8&psc=1

 

Good to know about the playsand - will the shrimp take care of that?

 

I'm still a little confused about the salt creep issue and why it's bad. I've dealt with it before (we call it salt deposits) and it basically means you just have to wipe down the glass once a week or so. Will this not take care of it?

 

So to be very clear, once I get live rock, remove the sponge, but keep the filter for flow?

 

Sorry if I sound like a broken record, but I want to be 100% sure I understand.

 

I did go to the fish store today and talk to the specialist/owner, who basically told me that a 5.5g reef with even just a few hermit crabs would not be responsible/ethical to keep due to the delicate nature of all marine animals. Even with the live rock, correct water flow and some macro algae, he says they would still die. If what he says is true, I'll save all this knowledge and set up a 20g reef a bit later. However, if it's nonsense, would someone please let me know? I don't want to depreciate the value of life for any animal.

 

About the UVB - that's really good information to know, so I'll have to find an alternative. There's a lot we don't know about land hermits, and need for UVA and UVB is part of that. :/ It's less simple for them, since their whole tank has to be pretty much enclosed for high humidity control, but I'll see if I can find a workable solution. There's a specific species I have (http://www1.prometheanplanet.com/rediscoveringdarwin/wp-content/gallery/pictures-from-the-expedition/strawberry-hermit.jpg) that is new to captivity and usually is only expected to live 1-3 years in captivity, and I have a strong suspicion that a lack of ammonia-free water and natural sunlight is why. However, the official word is as long as their tank is exposed to any level of sunlight, they are fine - seems like an oversimplification to me.

 

Again, thanks for all the responses! I'm slowly working my way through the libraries still, but I'm sick today and it is hard for me to keep ahold of complex ideas.

Will the shrimp take care of what? The silicates? I don't think so. And yes to the filter question if you want mechanical filtration. If not, get a powerhead. Salt creep is bad because its ugly, i assume its the same as what you call salt deposits and can be removed by wiping the glass. Your LFS owner IMO is wrong. There are plenty of tanks that small and with only some hermit crabs and maybe some coral you would be fine if you keep up research. If you want some fish, plan for the twenty.

[LarryMoeCurly]

I did go to the fish store today and talk to the specialist/owner, who basically told me that a 5.5g reef with even just a few hermit crabs would not be responsible/ethical to keep due to the delicate nature of all marine animals, even snails. Even with the live rock, correct water flow and some macro algae, he says they would still die. If what he says is true, I'll save all this knowledge and set up a 20g reef a bit later. However, if it's nonsense, would someone please let me know? I don't want to depreciate the value of life for any animal. If this is true, how can I prevent the tank being overgrown by algae, preferably without chemicals?

 

He is giving you false, outdated information. Look around this site and you will see plenty of successful "picos" (usually 5 gallons or less) with thriving fish, coral, and inverts. It takes more expertise, but it is certainly not impossible (nor unethical, if researched and done properly with suitable inhabitants). In your case, I do not think it will be too difficult to keep a few hermits alive.

[flutinkat]

Thank you so much! I will post pics as soon as I can get everything up and running (hopefully soon!). I'll plan for live rock, macro algae, a light if needed, sponge removed from the filter but the bubbler running on low/power head if salt creep becomes a dangerous issue for any animal in the tank to add that extra water flow, and the hermits added after everything is stabilized. Let me know if this is not correct and I'll fix it. Thanks again!

[seabass]

These are the lights already on the tank, which I was told were good for the plants. Are these acceptable for macro algae?

Those bulbs are suitable for macro algae.

 

Good to know about the playsand - will the shrimp take care of that?

Diatoms will result and ultimately take care of the silicate. Are you planning on keeping shrimp?

 

I'm still a little confused about the salt creep issue and why it's bad. I've dealt with it before (we call it salt deposits) and it basically means you just have to wipe down the glass once a week or so. Will this not take care of it?

If it would confine itself to the glass, then I might agree. It's so easy to just move the airstone to the freshwater side. And get a small powerhead for additional flow (like a Mini-Jet 606 at 82 – 153gph).

 

So to be very clear, once I get live rock, remove the sponge, but keep the filter for flow?

The filter is fine. You can run chemical media (in a media bag) in it, like Seagel or just activated carbon.

 

I did go to the fish store today and talk to the specialist/owner, who basically told me that a 5.5g reef with even just a few hermit crabs would not be responsible/ethical to keep due to the delicate nature of all marine animals, even snails.

In this particular instance, the shop owner is wrong. It sounds like that's his opinion. We have plenty of examples where this is contradicted.

 

...how can I prevent the tank being overgrown by algae, preferably without chemicals?

Nutrients should be kept under control (phosphate at 0.03ppm or less and nitrate at 10ppm or less).

[flutinkat]

Oh, I see the misunderstanding! Yes, the freshwater side already has a couple of ghost shrimp to start the cycling, and so far they are okay. That side does have a bubbler, which is why I'm reluctant to double up; I can easily see the poor shrimp getting tossed around by the water flow. Humidity has kept up really well, so it may be a non-issue in the first place and I can do without it. I'll keep you posted.

[fretfreak13]

About the salt creep thing, since it is really just an aesthetics thing go ahead and try the airstone. I'll bet you remove it in a week.

 

http://www.marineaquariumsa.com/imagehosting/14acba849d0707.jpg'>This is what salt creep looks like.

 

What humidity are you aiming for? Many chameleon keepers shoot for about 70% and achieve it in their all-screen cages through the use of live plants and multiple daily enclosure mistings. Some even run automated misting systems. Just throwing out ideas for ya!

[flutinkat]

I've thought about the automated systems, but I try to keep synthetics to a minimum since hermits tend to eat everything in their environment for the possibility of extra variety in nutrition. :/ Humidity goal is 80% in general, but they tend to like it more at 85%. Moss pits, bubblers and misting are the favored techniques in the community, although I don't mist if at all possible to avoid fluctuation, since condition fluctuation can be really bad for some of the exotic species. What live plants are you talking about? I'll do anything for easier humidity.

[flutinkat]

Oh, hrm, temp question. Since I'm from Texas and it gets hot here, what's the highest temperature they can be kept at? I imagine that marine crabs are sensitive to fluctuations as well.

[seabass]

Stability is important. You should keep it less than 84 degrees (but 80 degrees is better). A heater is key for stability even in the summer.

[fretfreak13]

Well, keep in mind I'm speaking from a chameleon owners experience. We have to use plants that we know aren't toxic to our little guys because many of ours also eat everything in sight, even dirt! We have to re-pot everything in organic soil so they don't ingest anything foreign, like the little white balls in some soils. http://www.chameleonforums.com/blogs/gerhartrx/523-chameleon-safe-plants.html'>Here's a chameleon-safe plant list. I don't know what in plants may be toxic to your hermits though, they are such different animals.

 

If you do decide to go with an automated system, I HIGHLY recommend Mist King!!! The all-black nozzles aren't an eyesore and can be put through screen or acrylic lids pretty easily. Their most basic setup is only about 100 bucks, and has enough power to run ten nozzles. Even with our 4ft tall cages, we normally only need two. Three at most. In the future I will be building a greenhouse to house my chams and the entire thing will be run by mist king.

[flutinkat]

Don't worry, I'll keep it stable! I keep my terrarium at 82 degrees in the day and 81 degrees at night (there's a slight temp drop like there would be naturally).

Ammonia was even higher today at 2.0. How high should I expect it to go? There was an ammonia and pH spike as well in the freshwater after adding the Petco shrimp...hmm....

Thanks for the info about the terrariums! I'm so paranoid about additives because mine are so small (some of them are less than a dime size with their shell), so I don't even re-pot, I just grow from scratch. You should have seen the feed store when I asked if they had dandelion seeds! It's nice to hear from other keepers, since most of the hermit people don't keep anything else.

[fretfreak13]

Absolutly. The chameleon keepers are all nuts. By "re-pot", mean they take the plant out of its pot, place it in the shower, and let the shower run on it for a half hour, pulling all the dirt out of the roots and washing down the leaves of pesticides. THEN they repot it, lol

 

I would also scour the net for dandelion seeds, but look on reptile feed sites. We use dandelion leaves to gut load crickets.

 

Seems us salt keepers always have menageries. I've had so many animals your head would probably explode. lol

[flutinkat]

We just have a small collection; 18 hermits and 4 cats (and now 7-8 shrimp and soon some marine hermits...). I'm still an apartment dweller so we're a bit limited.

 

I actually wound up getting the dandelion seeds for my store seed mix - I have a small online hermit crab food store to support my invert habit. The leaves aren't all that great for the hermits due to greenery and overload of certain nutrients, but now I know I can save them and maybe trade them for mealworms with reptile people.

Wound up having to take the cat to the vet for a full work-up, so it might be a bit before I can get my live rock...beginning of next month at the latest. I'll still keep everyone posted.

[flutinkat]

Update: I got the live rock and added it yesterday. I did finally keep the bubbler but split it with a gang valve so it's at a very low level that doesn't create salt creep. I also added in some of my smallest land hermit shells and am going to order some common periwinkle and some of the other shells suggested by marine invert people. Cycling continues; I've been seeing some nitrite level but the ammonia has not yet dropped to zero.

 

A couple of questions:

1) Do I need something to test for phosphates? Can someone recommend a good hydrometer? Another keeper with the same kind of setup says her marine hermits only leave the pool when the salinity is not correct, so I guess I need to keep an eye on that.

2) Can anyone suggest improvements on a feeding regimen? Extrapolating from a likely diet of wild marine hermits, I was going to feed some various freeze-dried proteins, sand dollars, cuttlebone, seaweed, and provide some macro-algae. I was also considering sparingly feeding Hikari Shrimp Cuisine.

 

Interesting fact about what I stated before regarding copper: copper and ferrous sulfate are, in fact, pesticides that are designed to remove invert pests from fish. However, copper is okay for inverts in very small amounts; their blood is copper based, and they will get the requisite amount from the saltwater mix alone. However, much like just a little extra iron won't hurt us, a little extra copper won't hurt them. No conclusive evidence on whether or not it shortens life span that I have found yet.

[seabass]

I did finally keep the bubbler but split it with a gang valve so it's at a very low level that doesn't create salt creep.

It might not seem like it, but it will slowly accumulate. I'm still not a fan of that idea.

 

... going to order some common periwinkle and some of the other shells suggested...

Aren't Periwinkles really small? My Blue Leg Hermits always seem to wear Cerith shells. I'm sure you can buy/order them cheaper, but take a look at this; it will give you an idea of what they will choose: http://www.liveaquaria.com/product/prod_display.cfm?c=497+526+1756&pcatid=1756

 

A couple of questions: 1) Do I need something to test for phosphates? Can someone recommend a good hydrometer? Another keeper with the same kind of setup says her marine hermits only leave the pool when the salinity is not correct, so I guess I need to keep an eye on that.

After the cycle has been established, I would test for nitrate and phosphate. You need a low range phosphate kit to determine if levels are within recommended range (0.000 to 0.003 ppm). Red Sea Pro make a readable kit. Regular use of a phosphate reducing filter media might make testing virtually unnecessary.

 

Any hydrometer sold for saltwater fish should be adequate. I currently use an Instant Ocean hydrometer that is OK.

 

2) Can anyone suggest improvements on a feeding regimen? Extrapolating from a likely diet of wild marine hermits, I was going to feed some various freeze-dried proteins, sand dollars, cuttlebone, seaweed, and provide some macro-algae. I was also considering sparingly feeding Hikari Shrimp Cuisine.

Like we said, we don't usually put much thought into what to feed hermit crabs (since they are left to scavenge left over food and dead snails (or other meaty food). I would choose a small pellet saltwater fish food. Pellets will sink to the bottom and will be fairly easy for the crabs to find, catch, and eat. Depending on the crabs you choose, you might pick a food with a little algae in it.

[Bett]

Flutinkat, I'm just wondering, did you come over from the hermit crab association? I was on there years ago, back when I had land hermits. I remember reading about how some people kept marine hermits even though it wasn't very common on the forums. Now I haven't had land hermits in a couple years and I only have a few blue leg marine ones in my reef tank. I was just thinking about how there's a completely different mentality between reef forums and the land hermit people for what we do with the crabs. We keep land crabs as the pet and main focus of out terrariums, but then on other times we toss marine hermits into our reefs just to keep the place clean and be part of the scavengers. It's interesting having been on both sides.

 

I used to sprout some millet from birdseed every now and then to let my crabs munch on. I tried adding a couple live plants to my tank once but they got chewed up by my crabs. One time I added a couple brown feeder crickets to the tank and the crickets happily bred like crazy in my coco husk substrate. My crabs went nuts and ate all the adult crickets and later on I had a ton of tiny crickets all over.

I kind of miss my land hermits, I wish I still had some around.

 

PM me if you ever need fresh, organic dandelion seeds or dried leaves. They grow all over in our fields and we never spray them with anything, so I'm sure your crabs would love them.